<script src="../src/dhtml/prototype.js"></script>
<script src="../src/dhtml/patch.js"></script>
<style>
.hide{
	display:none;
}
</style>
<input name="foo" data-onkeyup="text:div" />

<span data-bind="toggle:not(foo)" class="hide">Please enter a first name.</span>
<span data-bind="toggle:checkLength(foo)" data-aop="before:ddd" class="hide">Not eng!</span>
<div></div>
<script src="data-binding.js"></script>